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Journal of Neuroscience Research Nov 2017Succinylation of proteins is widespread, modifies both the charge and size of the molecules, and can alter their function. For example, liver mitochondrial proteins have...
Succinylation of proteins is widespread, modifies both the charge and size of the molecules, and can alter their function. For example, liver mitochondrial proteins have 1,190 unique succinylation sites representing multiple metabolic pathways. Succinylation is sensitive to both increases and decreases of the NAD -dependent desuccinylase, SIRT5. Although the succinyl group for succinylation is derived from metabolism, the effects of systematic variation of metabolism on mitochondrial succinylation are not known. Changes in succinylation of mitochondrial proteins following variations in metabolism were compared against the mitochondrial redox state as estimated by the mitochondrial NAD /NADH ratio using fluorescent probes. The ratio was decreased by reduced glycolysis and/or glutathione depletion (iodoacetic acid; 2-deoxyglucose), depressed tricarboxylic acid cycle activity (carboxyethyl ester of succinyl phosphonate), and impairment of electron transport (antimycin) or ATP synthase (oligomycin), while uncouplers of oxidative phosphorylation (carbonyl cyanide m-chlorophenyl hydrazine or tyrphostin) increased the NAD /NADH ratio. All of the conditions decreased succinylation. In contrast, reducing the oxygen from 20% to 2.4% increased succinylation. The results demonstrate that succinylation varies with metabolic states, is not correlated to the mitochondrial NAD /NADH ratio, and may help coordinate the response to metabolic challenge.
Topics: Animals; Cell Line, Tumor; Deoxyglucose; Mice; Mitochondrial Proteins; NAD; Organophosphonates; Oxidation-Reduction; Oxidative Phosphorylation; Succinates; Succinic Acid
PubMed: 28631845
DOI: 10.1002/jnr.24103 -
Clinical Chemistry May 2018There is growing interest in fructosamine, glycated albumin, and 1,5-anhydroglucitol (1,5-AG) as alternative measures of hyperglycemia, particularly for use in settings...
BACKGROUND
There is growing interest in fructosamine, glycated albumin, and 1,5-anhydroglucitol (1,5-AG) as alternative measures of hyperglycemia, particularly for use in settings where traditional measures (glucose and HbA1c) are problematic or where intermediate (2-4 weeks) glycemic control is of interest. However, reference intervals for these alternative biomarkers are not established.
METHODS
We measured fructosamine, glycated albumin, and 1,5-AG in a community-based sample of US black and white adults who participated in the Atherosclerosis Risk in Communities (ARIC) Study. We calculated reference intervals, evaluated demographic differences, and derived cutoffs aligned with current diagnostic cutpoints for HbA1c and fasting glucose.
RESULTS
In a healthy reference population of 1799 individuals (mean age, 55 years; 51% women; 15% black), the 2.5 and 97.5 percentiles, respectively, were 194.8 and 258.0 μmol/L for fructosamine, 10.7% and 15.1% for glycated albumin, and 8.4 and 28.7 μg/mL for 1,5-AG. Distributions differed by race, sex, and body mass index. Equivalent concentrations of fructosamine and glycated albumin corresponding to an HbA1c of 6.5% (96.5 percentile) were 270.2 μmol/L and 15.6%, respectively. Equivalent concentrations of fructosamine and glycated albumin corresponding to a fasting glucose of 126 mg/dL (93.9 percentile) were 261.7 μmol/L and 15.0%, respectively.
CONCLUSIONS
The reference intervals for these biomarkers should inform their clinical use. Diagnostic cutpoint equivalents for fructosamine and glycated albumin could be useful to identify persons with hyperglycemia in settings where fasting glucose or HbA1c are not available or where the interpretation of these traditional measures is problematic.
Topics: Deoxyglucose; Female; Fructosamine; Glycated Hemoglobin; Glycation End Products, Advanced; Humans; Male; Reference Standards; Serum Albumin; Glycated Serum Albumin
PubMed: 29436378
DOI: 10.1373/clinchem.2017.285742 -
Cell Reports Oct 2015Upon antigen recognition and co-stimulation, T lymphocytes upregulate the metabolic machinery necessary to proliferate and sustain effector function. This metabolic...
Upon antigen recognition and co-stimulation, T lymphocytes upregulate the metabolic machinery necessary to proliferate and sustain effector function. This metabolic reprogramming in T cells regulates T cell activation and differentiation but is not just a consequence of antigen recognition. Although such metabolic reprogramming promotes the differentiation and function of T effector cells, the differentiation of regulatory T cells employs different metabolic reprogramming. Therefore, we hypothesized that inhibition of glycolysis and glutamine metabolism might prevent graft rejection by inhibiting effector generation and function and promoting regulatory T cell generation. We devised an anti-rejection regimen involving the glycolytic inhibitor 2-deoxyglucose (2-DG), the anti-type II diabetes drug metformin, and the inhibitor of glutamine metabolism 6-diazo-5-oxo-L-norleucine (DON). Using this triple-drug regimen, we were able to prevent or delay graft rejection in fully mismatched skin and heart allograft transplantation models.
Topics: Allografts; Animals; CD8-Positive T-Lymphocytes; Cells, Cultured; Deoxyglucose; Diazooxonorleucine; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Glutamine; Glycolysis; Graft Rejection; Heart Transplantation; Metformin; Mice; Mice, Inbred BALB C; Mice, Transgenic; Phosphorylation; T-Lymphocytes, Regulatory
PubMed: 26489460
DOI: 10.1016/j.celrep.2015.09.036 -
Current Protocols May 2021The liver is central in maintaining glucose homeostasis. Indeed, impaired hepatic glucose uptake has been implicated in the development of hyperglycemia in type II...
The liver is central in maintaining glucose homeostasis. Indeed, impaired hepatic glucose uptake has been implicated in the development of hyperglycemia in type II diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD). However, current approaches to evaluate glucose mobilization rely on indirect measurements that do not provide spatial and temporal information. Here, we describe confocal-based intravital microscopy (IVM) of the liver that allows the identification of hepatocyte spatial organization and glucose transport. Specifically, we describe a method to fluorescently label hepatic landmarks to identify different compartments within the liver. In addition, we outline an in vivo fluorescent glucose uptake assay to quantitatively measure glucose mobilization in space and time. These protocols allow direct investigation of hepatic glycemic control and can be further applied to murine models of liver disease. © Published 2021. This article is a U.S. Government work and is in the public domain in the USA. Basic Protocol 1: Mouse surgical procedure and positioning for liver intravital imaging Basic Protocol 2: Fluorescent labeling and intravital imaging of mouse hepatic compartments Basic Protocol 3: Mouse hepatic glucose uptake assay and intravital imaging analysis.
Topics: 4-Chloro-7-nitrobenzofurazan; Animals; Deoxyglucose; Fluorescent Dyes; Glucose; Hepatocytes; Imaging, Three-Dimensional; Intravital Microscopy; Liver; Mice
PubMed: 34033261
DOI: 10.1002/cpz1.139 -
Journal of Nephrology Aug 2017Autosomal dominant polycystic kidney disease (ADPKD) is an inherited renal disease characterized by bilateral renal cyst formation. ADPKD is one of the most common rare... (Review)
Review
Autosomal dominant polycystic kidney disease (ADPKD) is an inherited renal disease characterized by bilateral renal cyst formation. ADPKD is one of the most common rare disorders, accounting for ~10% of all patients with end-stage renal disease (ESRD). ADPKD is a chronic disorder in which the gradual expansion of cysts that form in a minority of nephrons eventually causes loss of renal function due to the compression and degeneration of the surrounding normal parenchyma. Numerous deranged pathways have been identified in the cyst-lining epithelia, prompting the design of potential therapies. Several of these potential treatments have proved effective in slowing down disease progression in pre-clinical animal studies, while only one has subsequently been proven to effectively slow down disease progression in patients, and it has recently been approved for therapy in Europe, Canada and Japan. Among the affected cellular functions and pathways, recent investigations have described metabolic derangement in ADPKD as a major trait offering additional opportunities for targeted therapies. In particular, increased aerobic glycolysis (the Warburg effect) has been described as a prominent feature of ADPKD kidneys and its inhibition using the glucose analogue 2-deoxy-D-glucose (2DG) proved effective in slowing down disease progression in preclinical models of the disease. At the same time, previous clinical experiences have been reported with 2DG, showing that this compound is well tolerated in humans with minimal and reversible side effects. In this work, we review the literature and speculate that 2DG could be a good candidate for a clinical trial in humans affected by ADPKD.
Topics: Animals; Deoxyglucose; Disease Models, Animal; Disease Progression; Glycolysis; Humans; Kidney; Kidney Failure, Chronic; Polycystic Kidney, Autosomal Dominant; Renal Agents; Translational Research, Biomedical; Treatment Outcome
PubMed: 28390001
DOI: 10.1007/s40620-017-0395-9 -
Anesthesia and Analgesia Feb 2015The mechanisms of general anesthesia by volatile drugs remain largely unknown. Mitochondrial dysfunction and reduction in energy levels have been suggested to be...
BACKGROUND
The mechanisms of general anesthesia by volatile drugs remain largely unknown. Mitochondrial dysfunction and reduction in energy levels have been suggested to be associated with general anesthesia status. 2-Deoxy-D-glucose (2-DG), an analog of glucose, inhibits hexokinase and reduces cellular levels of adenosine triphosphate (ATP). 3-Nitropropionic acid is another compound which can deplete ATP levels. In contrast, idebenone and L-carnitine could rescue deficits of energy. We therefore sought to determine whether 2-DG and/or 3-nitropropionic acid can enhance the anesthetic effects of isoflurane, and whether idebenone and L-carnitine can reverse the actions of 2-DG.
METHODS
C57BL/6J mice (8 months old) received different concentrations of isoflurane with and without the treatments of 2-DG, 3-nitropropionic acid, idebenone, and L-carnitine. Isoflurane-induced loss of righting reflex (LORR) was determined in the mice. ATP levels in H4 human neuroglioma cells were assessed after these treatments. Finally, 31P-magnetic resonance spectroscopy was used to determine the effects of isoflurane on brain ATP levels in the mice.
RESULTS
2-DG enhanced isoflurane-induced LORR (P = 0.002, N = 15). 3-Nitropropionic acid also enhanced the anesthetic effects of isoflurane (P = 0.005, N = 15). Idebenone (idebenone + saline versus idebenone + 2-DG: P = 0.165, N = 15), but not L-carnitine (L-carnitine + saline versus L-carnitine + 2-DG: P < 0.0001, N = 15), inhibited the effects of 2-DG on enhancing isoflurane-induced LORR in the mice, as evidenced by 2-DG not enhancing isoflurane-induced LORR in the mice pretreated with idebenone. Idebenone (idebenone + saline versus idebenone + 2-DG: P = 0.177, N = 6), but not L-carnitine (L-carnitine + saline versus L-carnitine + 2-DG: P = 0.029, N = 6), also mitigated the effects of 2-DG on reducing ATP levels in cells, as evidenced by 2-DG not decreasing ATP levels in the cells pretreated with idebenone. Finally, isoflurane decreased ATP levels in both cultured cells and mouse brains (β-ATP: P = 0.003, N = 10; β-ATP/phosphocreatine: P = 0.006, N = 10; β-ATP/inorganic phosphate: P = 0.001, N = 10).
CONCLUSIONS
These results from our pilot studies have established a system and generated a hypothesis that 2-DG enhances anesthetic effects via reducing energy levels. These findings should promote further studies to investigate anesthesia mechanisms.
Topics: Adenosine Triphosphate; Anesthetics, Inhalation; Animals; Antimetabolites; Antioxidants; Carnitine; Deoxyglucose; Drug Synergism; Energy Metabolism; Humans; Isoflurane; Mice; Mice, Inbred C57BL; Nitro Compounds; Propionates; Ubiquinone; Vitamins
PubMed: 25390277
DOI: 10.1213/ANE.0000000000000520 -
European Journal of Nuclear Medicine... Jul 2020Imaging studies of cobalt toxicity from cobalt-chromium alloy arthroprosthetics have focused on the local intra-articular and peri-articular presentation from failing...
PURPOSE
Imaging studies of cobalt toxicity from cobalt-chromium alloy arthroprosthetics have focused on the local intra-articular and peri-articular presentation from failing joint replacements. Most studies investigating neurological findings have been small case series focused on the clinical findings of memory loss, diminished executive function, tremor, hearing and vision loss, depression, and emotional lability. This study utilizes software-based quantitative analysis of brain metabolism to assess the degree of hypometabolism and areas of susceptibility, determine if a pattern of involvement exists, and measure reversibility of findings after prosthetic revision to cobalt-free appliances.
METHODS
Over 48 months, 247 consecutive patients presenting to an orthopedic clinic with an arthroprosthetic joint containing any cobalt-chromium part were screened with whole blood and urine cobalt levels. A clinically validated inventory of 10 symptoms was obtained. Symptomatic patients with a blood cobalt level above 0.4 mcg/L or urine cobalt greater than 1 mcg/L underwent F-18 FDG PET brain imaging. Analysis was performed with FDA-approved quantitative brain analysis software with the pons as the reference region. Control group was the normal brain atlas within the software.
RESULTS
Of the 247 consecutively screened patients, 123 had blood and urine cobalt levels above the threshold. The 69 scanned patients had statistically significant regional hypometabolism and higher symptoms inventory. Fifty-seven patients were retained in the study. Distribution of hypometabolism was in descending order: temporal, frontal, Broca's areas, anterior cingulate, parietal, posterior cingulate, visual, sensorimotor, thalamic, and lastly caudate. Metal-on-metal (MoM) and metal-on-plastic (MoP) joint replacements produced similar patterns of hypometabolism. Of 15 patients with necessary revision surgery, 8 demonstrated improved metabolism when later re-scanned.
CONCLUSION
All scanned patients had regions of significant hypometabolism. Neurological toxicity from elevated systemic cobalt levels following arthroprosthetic joint replacement has a pattern of regional susceptibility similar to heavy metals and solvents, differing from classical dementias and may occur at blood and urine cobalt levels as low as 0.4 mcg/L and 1 mcg/L, respectively. Presently accepted thresholds for cobalt exposure and monitoring may need revision. Quantitative F-18 FDG PET brain imaging may aid in the decision process for treatment options and timing of possible medical versus surgical intervention.
Topics: Arthroplasty, Replacement, Hip; Brain; Fluorodeoxyglucose F18; Hip Prosthesis; Humans; Neuroimaging
PubMed: 31863138
DOI: 10.1007/s00259-019-04648-2 -
Nature Communications Dec 2018Surface receptor and transporter protein down-regulation is assumed to be exclusively mediated by the canonical multivesicular body (MVB) pathway and ESCRTs (Endosomal...
Surface receptor and transporter protein down-regulation is assumed to be exclusively mediated by the canonical multivesicular body (MVB) pathway and ESCRTs (Endosomal Sorting Complexes Required for Transport). However, few surface proteins are known to require ESCRTs for down-regulation, and reports of ESCRT-independent degradation are emerging, suggesting that alternative pathways exist. Here, using Saccharomyces cerevisiae as a model, we show that the hexose transporter Hxt3 does not require ESCRTs for down-regulation conferring resistance to 2-deoxyglucose. This is consistent with GFP-tagged Hxt3 bypassing ESCRT-mediated entry into intralumenal vesicles at endosomes. Instead, Hxt3-GFP accumulates on vacuolar lysosome membranes and is sorted into an area that, upon fusion, is internalized as an intralumenal fragment (ILF) and degraded. Moreover, heat stress or cycloheximide trigger degradation of Hxt3-GFP and other surface transporter proteins (Itr1, Aqr1) by this ESCRT-independent process. How this ILF pathway compares to the MVB pathway and potentially contributes to physiology is discussed.
Topics: Deoxyglucose; Down-Regulation; Endosomal Sorting Complexes Required for Transport; Endosomes; Glucose Transport Proteins, Facilitative; Intracellular Membranes; Lysosomes; Multivesicular Bodies; Proteolysis; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Signal Transduction; Vacuoles
PubMed: 30560896
DOI: 10.1038/s41467-018-07734-5 -
Molecules (Basel, Switzerland) Sep 2022Viral infection almost invariably causes metabolic changes in the infected cell and several types of host cells that respond to the infection. Among metabolic changes,... (Review)
Review
Viral infection almost invariably causes metabolic changes in the infected cell and several types of host cells that respond to the infection. Among metabolic changes, the most prominent is the upregulated glycolysis process as the main pathway of glucose utilization. Glycolysis activation is a common mechanism of cell adaptation to several viral infections, including noroviruses, rhinoviruses, influenza virus, Zika virus, cytomegalovirus, coronaviruses and others. Such metabolic changes provide potential targets for therapeutic approaches that could reduce the impact of infection. Glycolysis inhibitors, especially 2-deoxy-D-glucose (2-DG), have been intensively studied as antiviral agents. However, 2-DG's poor pharmacokinetic properties limit its wide clinical application. Herein, we discuss the potential of 2-DG and its novel analogs as potent promising antiviral drugs with special emphasis on targeted intracellular processes.
Topics: Antiviral Agents; COVID-19; Deoxyglucose; Glucose; Glycolysis; Humans; Mannose; SARS-CoV-2; Zika Virus; Zika Virus Infection
PubMed: 36144664
DOI: 10.3390/molecules27185928 -
Microbes and Infection 2023Viral infection treatment is a difficult task due to its complex structure and metabolism. Additionally, viruses can alter the metabolism of host cells, mutate, and...
Viral infection treatment is a difficult task due to its complex structure and metabolism. Additionally, viruses can alter the metabolism of host cells, mutate, and readily adjust to harsh environments. Coronavirus stimulates glycolysis, weakens mitochondrial activity, and impairs infected cells. In this study, we investigated the efficacy of 2-DG in inhibiting coronavirus-induced metabolic processes and antiviral host defense systems, which have not been explored so far. 2-Deoxy-d-glucose (2-DG), a molecule restricting substrate availability, has recently gained attention as a potential antiviral drug. The results revealed that 229E human coronavirus promoted glycolysis, producing a significant increase in the concentration of fluorescent 2-NBDG, a glucose analog, particularly in the infected host cells. The addition of 2-DG decreased its viral replication and suppressed infection-induced cell death and cytopathic effects, thereby improving the antiviral host defense response. It was also observed that administration of low doses of 2-DG inhibited glucose uptake, indicating that 2-DG consumption in virus-infected host cells was mediated by high-affinity glucose transporters, whose levels were amplified upon coronavirus infection. Our findings indicated that 2-DG could be a potential drug to improve the host defense system in coronavirus-infected cells.
Topics: Humans; Deoxyglucose; Virulence; Glycolysis; Glucose; Coronavirus; Antiviral Agents
PubMed: 37178787
DOI: 10.1016/j.micinf.2023.105150